Introduction

This is a collection of energy expenditure and energy balance studies. Use the table of contents above this headline to navigate and find the studies you want to read. The studies are all categorized by topic and sub-topic. Contact me at adam@sci-fit.net if you want to contribute studies or reviews to this collection.

Plain language explanations of central terms

All the relevant terms and definitions are organized below. These terms are central to understanding energy expenditure. Give it a quick read before diving into the research. Click the blue buttons and red footnotes to read relevant quotes from studies.

Thermogenesis

Thermogenesis is when the body produces heat (energy). As explained below, there are several ways this can happen.

Energy Expenditure (EE) and Energy Balance (EB)

The human body is always expending energy. Whether you are sitting, moving, eating, shivering, etc. The more active you are, the more energy you expend (energy out). The more energy you expend, the more food you need to eat to maintain body weight (energy in). You are in energy balance when you are eating the same amount of energy that you are expending. ~10% of the energy we eat is lost in feces, urine, or via the skin.

“In humans, about 90% of energy ingested is metabolizable energy, with the rest being lost in the feces, urine, or leaving the body via the skin” - Lam and Ravussin, 2016

The figure below shows how different amounts of lean body mass correlate with energy expenditure (more mass = more energy expended per 24h).

Total Daily Energy Expenditure (TDEE)

Your total daily energy expenditure is how much energy you expend every day. It is typically measured in kcal (kilocalories aka calories). According to the dietary guidelines of Health.gov, the average sedentary american requires 2,400 kcal (men) or 2,000 kcal (women) to maintain body weight. TDEE consists of resting metabolic rate, the thermic effect of food, and activity expenditure. These terms are explained further down.

Total energy expenditure (TEE) is composed of the energy costs of the processes essential for life (basal metabolic rate (BMR), 60–80% of TEE), of the energy expended in order to digest, absorb, and convert food (diet-induced thermogenesis, ~10%), and the energy expended during physical activities (activity energy expenditure, ~15–30%) - Heydenreich et al., 2017

Resting Metabolic Rate (RMR) aka Resting Energy Expenditure (REE)

Resting metabolic rate refers to how much energy your body expends to maintain basic physiological functions. As the name implies, it is measured at rest.

“RMR refers to the energy required to sustain the biochemical systems of the body at complete rest and accounts for ∼70% of TDEE in sedentary individuals [41].” - Lam and Ravussin, 2016

“RMR is the largest component of TDEE (60–75%), and represents the energy required to maintain essential vital functioning. Three-quarters of the variability in RMR is predicted by lean body mass [5].” - Donahoo et al., 2004

“Energy cost of physical activity is the most variable component of TDEE, which accounts for energy consumed in muscular work during spontaneous and voluntary exercise. It has been estimated that activity energy expenditure ranges from ∼15% in very sedentary individuals to up to 50% in highly active individuals [47].” - Lam and Ravussin, 2016

Physical activity is the third main determinant of TEE. It is defined as the additional energy expenditure above REE and TEF, which is required for performing bodily activity. It can be categorized into exercise related activity thermogenesis (EAT) and nonexercise activity thermogenesis (NEAT). Both vary widely within and between individuals. For the majority of subjects in industrialized countries exercise is believed to be negligible (13,15). - Loeffelholz, 2014

Non-Exercise Activity Thermogenesis (NEAT)

This is the energy you use during activity and movement outside of exercise.

Diet-Induced Thermogenesis (DIT) aka Thermic Effect of Food (TEF)

You expend energy digesting, absorbing, and storing foods. TEF/DIT accounts for about 10% of TDEE. Protein leads to the greatest diet-induced energy expenditure. Combined with its positive effects on satiety and lean body mass, protein is an important macronutrient during weight loss.

“DIT is the increase in energy expenditure associated with the digestion, absorption, and storage of food and accounts for approximately 10– 15% of TDEE [6].” - Donahoo et al., 2004

“TEF refers to the energy expenditure that relates to food consumption, i.e., energy required to digest, absorb, assimilate, and store nutrients, and thus is dependent on the amount and the type of nutrients consumed. TEF has been reported as 5–10%, 0–3% and 20–30% of the energy content of carbohydrates, lipids, and proteins respectively [50] and in the case of energy balance on a Western diet accounts for ∼10% of TDEE [51].” - Lam and Ravussin, 2016

“In conclusion, the main determinants of diet-induced thermogenesis are the energy content and the protein- and alcohol fraction of the diet. Protein plays a key role in body weight regulation through satiety related to diet-induced thermogenesis.” - Westerterp, 2004

Excess Post-Exercise Oxygen Consumption (EPOC)

After exercise, your body continues to expend energy beyond what it normally would if you were sedentary. This has also been called the Afterburn Effect. Sprints and strength training seem to increase EPOC more than low intensity steady state training (i.e. jogging).

“In the recovery period after exercise there is an increase in oxygen uptake termed the 'excess post-exercise oxygen consumption' (EPOC), consisting of a rapid and a prolonged component.” - Børsheim and Bahr, 2003

Adaptive Thermogenesis (AT)

When we lose weight, the body might reduce its energy expenditure to prevent further weight loss. It will also try to regain lost weight.

“The adaptive component of thermogenesis that has been documented under conditions of negative energy balance is under the influence of hormones and sympathetic nervous system activity that have been shown to explain variations in EE beyond what could be explained by changes in body weight and composition.9, 37, 38, 39, 40, 41, 42, 43, 44 Indeed, leptin,11, 39, 45 insulin,46, 47, 48 thyroid hormones 9, 38, 41, 43, 45 as well as sympathetic activity37, 41, 42, 45 have been shown in several studies to be associated with a greater than predicted variation in EE. Moreover, fat depletion per se has also been considered as a determinant factor for adaptive thermogenesis.7, 49” - Major et al., 2007

“The over 80% recidivism rate to pre-weight loss levels of body fatness after otherwise successful weight loss is due to the coordinate actions of metabolic, behavioral, neuroendocrine, and autonomic responses designed to maintain body energy stores (fat) at a CNS- defined “ideal”. This “adaptive thermogenesis” creates the ideal situation for weight regain and is operant in both lean and obese individuals attempting to sustain reduced body weights. Much of this opposition to sustained weight loss is mediated by the adipocyte-derived hormone “leptin””. - Rosenbaum and Leibel, 2010

Newsletter

Stay updated on the science.

Sign up for the newsletter.

Name (optional)

Email

Interesting papers

Click the footnotes to read quotes from the papers.

Steady state models provide an invalid estimate of intermittent resistance-exercise energy costs (PDF Download Available)1“Resistance training energy costs as described here are not properly portrayed by steady state oxygen uptake models - indeed, such application lacks validity. We instead suggest that the energy costs of brief, intense, intermittent exercise should be quantified in the context of a capacity estimate, where a bout of exercise and/or amount of work (J) completed is associated with a specific energy cost (kJoules). For resistance exercise, we propose linear models that measure work and energy bouts as an alternative to the steady state rate model.”

Re-interpreting anaerobic metabolism: an argument for the application of both anaerobic glycolysis and excess post-exercise oxygen comsumption (EPOC)2“Care must be taken when using O2 uptake alone to quantify energy expenditure because various high-intensity exercise models reveal that O2 uptake can lag behind estimated energy demands or exceed them. The independent bioenergetics behind anaerobic glycolysis and mitochondrial respiration can acknowledge these discrepancies. Anaerobic glycolysis is an additive component to an exercise O2 uptake measurement. Moreover, it is the assumptions behind steady-state O2 uptake that do not permit proper interpretation of energy expenditure during EPOC; 1 l O2 not = 20.9 kJ. Using both the O2 deficit and a modified EPOC for interpretation, rather than one or the other, leads to a better method of quantifying energy expenditure for higher intensity exercise and recovery.”

Modeling the Total Energy Costs of Resistance Exercise: a Work in Progress4“We present an aerobic and anaerobic, exercise and recovery energy cost model of intermittent energy costs utilizing task (work, Joules) as opposed to rate (per minute) measurements. Low to moderate intensity steady state exercise energy costs are typically portrayed as the volumetric rate at which oxygen is consumed (VO2 L min–1), where a proportionate upward climbing linear relationship is profiled with an increasing power output; add to this the concept of the anaerobic threshold and energy costs increase with more intense aerobic exercise in disproportion to VO2 L min–1 measurements. As a per task function, intermittent work and recovery bouts contain a combined estimate of total costs, that is as kJ or kcal (not kJ.min-1 or kcal.min-1)”

Resistance to weight gain during overfeeding: a NEAT explanation5“Individuals in whom overeating effectively activates NEAT dissipate as much as 69% of the excess energy as heat. Those less able to activate NEAT store a higher proportion of the excess calories as fat. Other studies have shown that genotype is an important determinant of resistance to overfeeding-induced weight gain. Spontaneous weight gain is accompanied by rises in plasma norepinephrine, insulin, and leptin levels, suggesting that a change in autonomic nervous system activity or in pattern of hormonal secretion might play a role in the activation of overeating-induced NEAT”

Using Sit-to-Stand Workstations in Offices: Is There a Compensation Effect?9“The findings suggest that introducing a sit-to-stand workstation can significantly reduce sedentary time and increase light activity levels during working hours. However, these changes were compensated for by reducing activity and increasing sitting outside of working hours. An intervention of a sit-to-stand workstation should be accompanied by an intervention outside of working hours to limit behavior compensation.”

Energy Expenditure (EE)

General reviews (8)

The impact of exercise and diet restriction on daily energy expenditure “The hypothesis is that combining diet and exercise will accelerate fat loss, preserve fat-free weight and prevent or decelerate the decline in resting metabolic rate more effectively than with diet restriction alone. The optimal combination of diet and exercise, however, remains elusive. It appears that the combination of a large quantity of aerobic exercise with a very low calorie diet resulting in substantial loss of bodyweight may actually accelerate the decline in resting metabolic rate. These findings may cause us to re-examine the quantity of exercise and diet needed to achieve optimal fat loss and preservation of resting metabolic rate.”

Quantifying the Immediate Recovery Energy Expenditure of Resistance Training (PDF Download Available): “The energy expenditure of recovery is essentially all-aerobic; lactate and fat appear to be the major fuels oxidized in recovery (neither consists of anaerobic metabolic breakdown), non–steady-state O 2 uptake plummets rapidly, whereas CO 2 production appears to surge immediately in recovery, and EPOC has been suggested to not represent glycolytic ATP resynthesis; all of these concepts are effectively acknowledged by a single recovery energy expenditure conversion of 1 L of O 2 uptake = 19.6 kJ. This conversion can be used as a standard means of quantifying (aerobic) recovery energy expenditure immediately after a single bout of weight lifting or in-between sets of weight lifting.”

Contributing factors and variability of energy expenditure in non-obese, obese, and post-obese adolescents: “The objectives of this paper were to review the contributing factors of the main components of daily EE (DEE) and the inter-individual variability in these components in non-obese (NOb), obese (Ob), and post-obese (POb) adolescents. Body composition especially fat-free mass (FFM), is the major determinant of the basal metabolic rate which contributes 50-70% of DEE, whereas fat mass (FM) is a significant factor only in obese subjects. Physical activity is the second main variation factor of DEE, whereas growth, the thermic effect of food, and thermoregulation are generally of marginal importance.”

Fat and carbohydrate overfeeding in humans: different effects on energy storage: “Carbohydrate overfeeding produced progressive increases in carbohydrate oxidation and total energy expenditure resulting in 75-85% of excess energy being stored. Alternatively, fat overfeeding had minimal effects on fat oxidation and total energy expenditure, leading to storage of 90-95% of excess energy. Excess dietary fat leads to greater fat accumulation than does excess dietary carbohydrate, and the difference was greatest early in the overfeeding period. ”

Physical activity, total and regional obesity: dose-response considerations “In response to well-controlled, short-term trials, increasing physical activity expressed as energy expended per week is positively related to reductions in total adiposity in a dose-response manner. Although physical activity is associated with reduction in abdominal and visceral fat, there is insufficient evidence to determine a dose-response relationship.”

Using Sit-to-Stand Workstations in Offices: Is There a Compensation Effect? “The findings suggest that introducing a sit-to-stand workstation can significantly reduce sedentary time and increase light activity levels during working hours. However, these changes were compensated for by reducing activity and increasing sitting outside of working hours. An intervention of a sit-to-stand workstation should be accompanied by an intervention outside of working hours to limit behavior compensation.”

Potential Causes of Elevated REE following High-Intensity Exercise “Under energy balance conditions REE increased 22 hours following both moderate intensity and high intensity exercise. Exercise-induced muscle damage/repair and increased sympathetic tone may contribute to increased REE whereas uncoupled phosphorylation does not. These results suggest that moderate to high intensity exercise may be valuable for increasing energy expenditure for at least 22 hours following the exercise.”

One-set resistance training elevates energy expenditure for 72 h similar to three sets: “REE was significantly (p < 0.05) elevated (~5% or ~ 400 kJ day−1) in both the protocols at 24, 48, and 72 h post RT bout compared with baseline (...) A one-set RT bout following the ACSM guidelines for RT and requiring only ~ 15 min to complete was as effective as a three-set RT bout (~ 35 min to complete) in elevating REE for up to 72 h post RT in overweight college males”

Energy Cost of Resistance Exercises: an Uptade: “(...) it is concluded that knowledge on the energy cost in resistance exercises is in its early days and that much research is warranted before appropriate reference values may be proposed.”

Constrained Total Energy Expenditure and the Evolutionary Biology of Energy Balance: “The human body adapts dynamically to maintain total energy expenditure, TEE, within a narrow physiological range. Rather than increasing with physical activity in a dose-dependent manner, experimental and ecological evidence indicates that TEE is a relatively constrained product of our evolved physiology. The body adapts to changes in physical activity to keep total energy expenditure in check.”

Neurotrophic factor control of satiety and body weight: “Energy balance--that is, the relationship between energy intake and energy expenditure--is regulated by a complex interplay of hormones, brain circuits and peripheral tissues. Leptin is an adipocyte-derived cytokine that suppresses appetite and increases energy expenditure. Ironically, obese individuals have high levels of plasma leptin and are resistant to leptin treatment. Neurotrophic factors, particularly ciliary neurotrophic factor (CNTF) and brain-derived neurotrophic factor (BDNF), are also important for the control of body weight. CNTF can overcome leptin resistance in order to reduce body weight, although CNTF and leptin activate similar signalling cascades. Mutations in the gene encoding BDNF lead to insatiable appetite and severe obesity.”

Effect of acute resistance exercise on postexercise oxygen consumption and resting metabolic rate in young women “Resting metabolic rate was increased by 4.2% (p<.05) from Day 1 (morning prior to exercise: 1,419 +/- 58 kcal/24hr) compared to Day 2 (16 hr following exercise: 1,479 +/- kcal/24hr). Resting fat oxidation as determined by the respiratory exchange ratio was also significantly elevated on Day 2 compared to Day 1. These results indicate that among young women, acute strenuous resistance exercise of the nature used in this study is capable of producing modest but prolonged elevations of postexercise metabolic rate and possibly fat oxidation.”

Other (1)

Re-interpreting anaerobic metabolism: an argument for the application of both anaerobic glycolysis and excess post-exercise oxygen comsumption (EPOC) “Care must be taken when using O2 uptake alone to quantify energy expenditure because various high-intensity exercise models reveal that O2 uptake can lag behind estimated energy demands or exceed them. The independent bioenergetics behind anaerobic glycolysis and mitochondrial respiration can acknowledge these discrepancies. Anaerobic glycolysis is an additive component to an exercise O2 uptake measurement. Moreover, it is the assumptions behind steady-state O2 uptake that do not permit proper interpretation of energy expenditure during EPOC; 1 l O2 not = 20.9 kJ. Using both the O2 deficit and a modified EPOC for interpretation, rather than one or the other, leads to a better method of quantifying energy expenditure for higher intensity exercise and recovery.”

Resistance to weight gain during overfeeding: a NEAT explanation “Individuals in whom overeating effectively activates NEAT dissipate as much as 69% of the excess energy as heat. Those less able to activate NEAT store a higher proportion of the excess calories as fat. Other studies have shown that genotype is an important determinant of resistance to overfeeding-induced weight gain. Spontaneous weight gain is accompanied by rises in plasma norepinephrine, insulin, and leptin levels, suggesting that a change in autonomic nervous system activity or in pattern of hormonal secretion might play a role in the activation of overeating-induced NEAT”

Physical activity and resting metabolic rate: “Many studies have shown that long-term training increases RMR, but many other studies have failed to find such effects. Data concerning long-term effects of training are potentially confounded by some studies not leaving sufficient time after the last exercise bout for the termination of the long-term EPOC. Long-term effects of training include increases in RMR due to increases in lean muscle mass. Extreme interventions, however, may induce reductions in RMR, in spite of the increased lean tissue mass, similar to the changes observed in animals in response to flight.”

Variability of measured resting metabolic rate: “Repeated morning and evening measurements of RMR were stable and highly correlated. Day-to-day measurements of RMR were not significantly different. RMR measured in the afternoon after a 4-h fast and exercise was ≈100 kcal/d higher than RMR measured in the morning”

Elevated metabolic rates in obesity: “The high R.M.R. in the obese state was related not to the excess fat but to a 36% and 32% increase in the lean body mass of the men and women respectively. The R.M.R.s of 30 patients measured during weight-loss fell. The increase in R.M.R. in obesity is an important mechanism for achieving energy balance, whereas the progressive fall in R.M.R. during slimming demonstrates the need for a permanent reduction in food intake if energy balance is to be maintained on reaching normal weight. Measuring only the R.M.R. in the obese state is unlikely to help in understanding the pathogenesis of obesity.”

Reviews (6)

Intermittent resistance exercise: evolution from the steady state: “Oxygen uptake measurements are without question useful and a staple measurement for the estimation of exercise energy costs. However, steady state models cannot be used to successfully model intermittent resistance exercise energy costs. Our laboratory has taken steps to avoid such comparisons between these discrepant exercises. We have separated out exercise and recovery periods during resistance training and utilize capacity (kJ) estimates as opposed to rate measures (kJ min-1). Moreover, we avoid anaerobic threshold concepts as applied to resistance exercise. When viewed accordingly, resistance exercise energy costs are opposite those of the steady state model: exercise oxygen uptake is highest for steady state exercise and lowest for resistance exercise, recovery oxygen uptake can be the highest energy cost for resistance exercise whereas for steady state exercise it may or may not be meaningful, and anaerobic energy costs represent a significant component of resistance exercise that plays little to no role with steady state exercise.”

Re-interpreting anaerobic metabolism: an argument for the application of both anaerobic glycolysis and excess post-exercise oxygen comsumption (EPOC) “Care must be taken when using O2 uptake alone to quantify energy expenditure because various high-intensity exercise models reveal that O2 uptake can lag behind estimated energy demands or exceed them. The independent bioenergetics behind anaerobic glycolysis and mitochondrial respiration can acknowledge these discrepancies. Anaerobic glycolysis is an additive component to an exercise O2 uptake measurement. Moreover, it is the assumptions behind steady-state O2 uptake that do not permit proper interpretation of energy expenditure during EPOC; 1 l O2 not = 20.9 kJ. Using both the O2 deficit and a modified EPOC for interpretation, rather than one or the other, leads to a better method of quantifying energy expenditure for higher intensity exercise and recovery.”

Estimating exercise energy expenditure (6)

Estimating the Energy Costs of Intermittent Exercise: “We hypothesize that if the aerobic-only energetic profile of steady state exercise can be used to estimate the energetics of non-steady state and intermittent exercise, then the converse also must be true. In fact, reasonable estimates of energy costs to work volumes or work rates can be demonstrated under steady state, non-steady state and intermittent conditions; the problem with the latter two is metabolic variability. Using resistance training as a model, estimates of both aerobic and anaerobic energy cost components, as opposed to one or the other, have reduced the overall energetic variability that appears inherent to brief, intense, intermittent exercise models.”

Modeling the Total Energy Costs of Resistance Exercise: a Work in Progress “We present an aerobic and anaerobic, exercise and recovery energy cost model of intermittent energy costs utilizing task (work, Joules) as opposed to rate (per minute) measurements. Low to moderate intensity steady state exercise energy costs are typically portrayed as the volumetric rate at which oxygen is consumed (VO2 L min–1), where a proportionate upward climbing linear relationship is profiled with an increasing power output; add to this the concept of the anaerobic threshold and energy costs increase with more intense aerobic exercise in disproportion to VO2 L min–1 measurements. As a per task function, intermittent work and recovery bouts contain a combined estimate of total costs, that is as kJ or kcal (not kJ.min-1 or kcal.min-1)”

Steady state models provide an invalid estimate of intermittent resistance-exercise energy costs (PDF Download Available) “The prototype modeling of biological energy exchange invokes per minute measurements of oxygen uptake (l min-1), including exercise. While dedicated to steady rate power outputs, the oxygen uptake rate function model is now appropriated to intermittent exercise as well with resistance training serving as a primary example. Resistance training energy costs as described here are not properly portrayed by steady state oxygen uptake models - indeed, such application lacks validity. We instead suggest that the energy costs of brief, intense, intermittent exercise should be quantified in the context of a capacity estimate, where a bout of exercise and/or amount of work (J) completed is associated with a specific energy cost (kJoules). For resistance exercise, we propose linear models that measure work and energy bouts as an alternative to the steady state rate model.”

Measurement Methods for Physical Activity and Energy Expenditure: a Review: “In summary, there is no single best method that can assess all aspects of physical activity and energy expenditure. Therefore, as suggested by Troiano [94], the choice of assessment instrument depends on what aspect of physical activity the researcher wants to measure, characteristics of the target population, and whether the data will be used to describe groups or individuals.”

ENERGY EXPENDITURE IN STRENGTH TRAINING: A CRITICAL APPROACH: “Comparing training protocols considering the ST variables separately seems to be a mistake, because it seems impossible to dissociate them. The use of work units (W = sets x repetitions x load), together with the sum of measurements for the execution and the recovery phase (EPOC), seems to be the most consistent approach to understand EE in ST, being that EE increases with increasing W. A better understanding of the effect of the different variables can therefore be achieved, possibly considering the absolute values observed (kcal or L of O2) instead of relative values (kcal/min).”

Estimating free-living human energy expenditure: Practical aspects of the doubly labeled water method and its applications: “The DLW method was introduced for human use approximately 30 years ago [10]. This method provides information on TEE in free-living individuals over a period of 4-20 days. The principle of the method is as follows. Subjects receive a loading dose of water labeled with the stable 2H and 18O isotopes, and these isotopes mix with the hydrogen and oxygen in body water within a few hours. As energy is expended, CO2 and water are excreted. The CO2 is lost from the body only via the breath, while the water (including both 2H and 18O) is lost not only via the breath but also in urine, sweat, and through other means such as evaporation.”

Metabolic adaptation to weight loss: implications for the athlete: “In response to weight loss, reductions in TDEE, BMR, EAT, NEAT, and TEF are observed. Due to adaptive thermogenesis, TDEE is lowered to an extent that exceeds the magnitude predicted by losses in body mass. Further, research indicates that adaptive thermogenesis and decreased energy expenditure persist after the active weight loss period, even in subjects who have maintained a reduced body weight for over a year [14,48]. These changes serve to minimize the energy deficit, attenuate further loss of body mass, and promote weight regain in weight-reduced subjects.”

Metabolic and Behavioral Compensatory Responses to Exercise Interventions: Barriers to Weight Loss - King - 2007 - Obesity - Wiley Online Library: “The purpose of this review is to highlight the various metabolic and behavioral compensatory responses that could reduce the effectiveness of exercise and explain why some individuals experience a lower than expected weight loss. We propose that the extent and degree of compensation will vary between individuals. That is, some individuals will be predisposed to compensatory responses that render them resistant to the weight loss benefits theoretically associated with an exercise-induced increase in energy expenditure. Therefore, given the inter-individual variability in behavioral and metabolic compensatory responses, exercise prescriptions might be more effective if tailored to suit individuals.”

Models of energy homeostasis in response to maintenance of reduced body weight “Following initial weight loss (10%), resting (REE) and non-resting (NREE) EE were significantly below those predicted on the basis of the amount and composition of weight lost. Further reductions below predicted values of NREE but not REE occurred following an additional 10% weight loss. Changes in body weight, composition, and/or energy stores were significantly correlated with changes in EE.”

Underfeeding and body weight regulation in normal-weight young men “These results indicate that energy balance is regulated by adaptive variations in both energy intake and energy expenditure in normal-weight young men leading unrestricted lives but do not support the hypothesis that energy-wasting mechanisms contribute substantially to body energy regulation.”

Changes in energy expenditure resulting from altered body weight “Maintenance of a reduced or elevated body weight is associated with compensatory changes in energy expenditure, which oppose the maintenance of a body weight that is different from the usual weight. These compensatory changes may account for the poor long-term efficacy of treatments for obesity.”

Biology's response to dieting: the impetus for weight regain “The preponderance of evidence would suggest that the biological response to weight loss involves comprehensive, persistent, and redundant adaptations in energy homeostasis and that these adaptations underlie the high recidivism rate in obesity therapeutics. ”

A Missing Link in Body Weight Homeostasis: The Catabolic Signal of the Overfed State “Mammals regulate fat mass so that increases or reductions in adipose tissue mass activate responses that favor return to one’s previous weight. A reduction in fat mass activates a system that increases food intake and reduces energy expenditure; conversely, overfeeding and rapid adipose tissue expansion reduces food intake and increases energy expenditure. With the identification of leptin nearly two decades ago, the central circuit that defends against reductions in body fat was revealed. However, the systems that defend against rapid expansion of fat mass remain largely unknown. Here we review the physiology of the overfed state and evidence for a distinct regulatory system, which unlike the leptin-mediated system, we propose primarily measures a functional aspect of adipose tissue and not total mass per se.”

The influence of thermic effect of food on satiety “TEF was 261+/-59, 92+/-67 and 97+/-71 kJ over 7 h after the HP, HC and HF meals, respectively. The HP meal was the most thermogenic (P < 0.001) and it determined the highest sensation of fullness (P=0.002). There were no differences in the sensations and thermic effect between fat and carbohydrate meals. A significant relationship linked TEF to fullness sensation (r=0.41, P=0.025). Energy intake from the test meal was comparable after HP, HC and HF meals.”

Diet induced thermogenesis “In conclusion, the main determinants of diet-induced thermogenesis are the energy content and the protein- and alcohol fraction of the diet. Protein plays a key role in body weight regulation through satiety related to diet-induced thermogenesis.”

Thermic effect of food, exercise, and total energy expenditure in active females “The high protein meal elicited a 30.39% and 98.15% greater increase in TEF compared to the low protein meal (p=.006) and fasted state (p<.001), respectively. The low protein meal resulted in 94.34% greater TEF compared to fasted (p<.001). Combined with exercise, high protein meal TEF was significantly greater compared to fasted (p=.010) but was not significantly greater than the low protein meal (p=.122). Significant differences were not found between the low protein meals with exercise compared to fasted conditions (p=.094).”

The effects of high protein diets on thermogenesis, satiety and weight loss: a critical review “There is convincing evidence that a higher protein intake increases thermogenesis and satiety compared to diets of lower protein content. The weight of evidence also suggests that high protein meals lead to a reduced subsequent energy intake. Some evidence suggests that diets higher in protein result in an increased weight loss and fat loss as compared to diets lower in protein, but findings have not been consistent.”